Tensioning device for sewing-machines.



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Specilcation of Letters Patent.

TENSIONING DEVICE FOB SEWING-MACHINES.

Patented Nov. 29, 1917.

vf Application filed October 12,1914, Serial No. 866,382. Renewed May 10, 1917. Serial No. 167,804.

To` all whom it may concern:

Be itjknown that we, PETER RAsMUssEN and MANUEL F. GOULARTE, citizens of the United States, residing lat Selma,` in the countyrof Fresno and State of California, haveinvented certain new and useful Improvements in Tensioning Devices for Sewing-Machines, of which the following is a specification, reference being had to the accompanying drawings. ,j This invention relates to an improved thread tensioning device for` sewing ma chines and more particularly to a device of this character which is commonly employed in connection with shoe sewing machines.

The present invention has for its primary object to produce a simple, reliable, and effective tensioning means for machines of the above character which may be easily and quickly adjusted to vary the tension upon the thread.

The inventionV has for another object `to provide a tension regulating device which is simple and durable in its construction, is not liable to get outof order, and maybe manufactured atcomparatively small cost.

`,W ith the above Vand other objects in view, our invention consists 1n the novel features of construction, combination, and arrangement of parts to be hereinafter more fully described, claimed, and illustrated in the accompanying drawing, in which, j

Figure 1 is a front elevation-showing our improved thread tensioning devicein its preferred embodiment;`

Fig. 2 is a side elevation;

Fig. 3 is a section taken onthe line 3-3 of Fig. 2;

Fig. l is a section taken on the line 1 -4 ofFig.2;a-nd 1 Fig. 5 is a detail perspective view of one of the parts. n L

Referring in detail to Vthe drawing, 5

designates a stationary bar which is suitably mounted upon the frame of the machine andl secured in place by means of bolts indicated at 6. This bar is provided with a widened end portion 7 having an obliquely inclined edge face indicated at 8. From the inner end of this inclined face of the bar 5, the edge of the bar is inwardly curved as at 9, said curved edge extending through an arc of substantially 90. The bar 5 is slightly reduced inl width from one end of this curve to a point in spaced relation to the end of the bar, as indicated at 10. Adjacent to the end of this latter portion of the body bar 5, guide eye 11 is secured therein. The curved edge 9 and the reduced portion 10 of the bar 5 has integrally formed thereon adcontinuous longitudinally extending rib 12, the purpose of which will be hereinafter pointed out.

i A cast metal plate 13 ofchannel-shaped form in cross-section is provided with ears 14 upon its parallel side walls at one of their ends'which are pivotally mounted as at 15 upon the widened end 6 of the bar 5. The parallel` walls or flanges 16 of this channelshaped casting are spaced apart a sufficient distance to receive between them the body bar5, when said casting is arranged in substantial parallel relation to the same. The connecting wall 13 between the flanges 16 is cutaway for a portion of its length to produce ,a` slot 17, and upon the corresponding edges of the flanges 16 and projecting Voutwardly from said slot, the ears 18 are formed. Between these ears a peripheral grooved thread guide wheel or roller 19 is rotatably mounted. The transverse connecting wall 13"bet.ween the flanges 16 is further provided adjacent to its outer end with an opening 20.. This openingis adapted to receive a threaded bolt 21 which is fixed at one of Vits ends in the relatively narrow end portion of the body bar 5. A. coil spring 22 is arranged upon said bolt and `disposed be* tweensaid bar and the intermediate wall 13 of thechannel casting 13. 23 indicates an adjusting nut which is threaded upon the end of the bolt 21 and bears against the wall 13. The casting 13 may be readily adjusted with respect to the bar 5 by turning said nut.

v It will be observed from reference to Figs. 1 and e of the drawing, that the guide eye the slot 17 in the casting 13 and is slightly spaced from the grooved wheel 19.

In the use of our invention, the thread indicated at T is passed through this eye and under the wheel 19 between the saine and the longitudinally extending rib 12 formed upon the edge of the bar 5. The thread is then passed over the beveled or inclined edge face 8 of said bar to the bobbin or spool upon which it is adapted to be wound. By now screwing the nut 23 inwardly lupon the bolt 21, the casting 13 which carries the wheel 19 will be forced inwardly toward said bar, and the rib 12 thereon received in the peripheral groove of the wheel 19. This rib exerts a A11 on the bar 5 projects `outwardly through pressure or tension upon the thread as it 'advantages of our invention will be clearly and fully understood. The device may be readily mounted upon shoe sewing machines of the type now in 'general use without necessitating any material alterations in their construction. It will not Vlose its efficiency after a short period of use' as 1s the' case vwith tensioning devices employing leaf springs or analogous resilient thread engaging elements. As the rib l2 fits within the 4groove-'of the guide wheel over which the thread passes, it will also be manifest that this rib will effectually prevent all possibility of the thread becoming disengaged from the groove of the wheel in the operation of the machine. As 4our invention 'consists of very few parts which are all of simple form, it will further be appreciated that the device can be constructed at small manufacturing cost. i

Vhile' we have above described thelpreferred construction 'and arrangement Vofthe several elements employed -it will be understood that the device issus'ceptible of co-nsiderable modification therein and we therefore reserve the privilege of resorting to all such legitimate changes as vmay be fairly embodied within the spirit'a-nd Yscope of the invention as claimed.

.Having thus describedour invention, what we desire to claim and secure by Letters Patl. A thread tensioning deviceincluding a bodybar provided upon one edge with a longitudinally extending rib a wheel carry ing element adjustably mounted upon said bar, a peripherally groovediguide'wheel for the thread mounted upon said element, and meansmounted upon said barfor adjusting said element with Irespect to the b'ar to en- VCopies of this patent may bebtained for amasar' gage the rib within the groove of said wheel and uponthe thread. z

2. A thread tensioningdeviceincluding a body bar, a-channelfshaped member pivotally mounted at one lof its ends upon said bar, the opposed walls of said'memberbeing disposed upon'opposite sides of `the bar,` said channel-shaped Amember beingfprovided with a slot in its intermediate wall, a periph# erally grooved guide`-wheel for the thread mounted upon said member and extending into said slot, -a-'longitudinally extending rib on the edge of the body bar, and means for adjusting said channel-shaped member 65 ulpon the bar v'to dispose-'said rib Withinthe groove fof the guidewheel and upon the thread. 5.

3. -A thread tensioning device including a body bar having a longitudinally vc urfv'ed 7`0 edge portion and provided thereon with a rib, said rib 'extending beyond the curved portion ofthe -bar longitudinally thereof5 Aa ehanneleshapedmember fpivotally" mounted at one of -its ends upon the bodybar, a 75 peripherally grooved guidewheel carried by said men'iben'the Vgroove of 'said wheel-being adapted to receive the cliirved portion of said rib, a guide eye-fixed in sai-d bar, and means for `adjusting said channel-shaped member upon the body bar to vary the pressure'of said rib upon `thethre'ad in the groove of theguide wheel.. v y i f Y 4; A thread tensioning device includinga fixed bodybarz a 'channel-'shaped-lelement 85 Inovablyf mounted upon said. Vbody bar, a thread guide mounted upon said elementV and rprojecting'infto the channel of 'said ele- -111e1it;`means for adjusting saidrelement to p'osition'the threadguidewith respectfo the 9U bar, and means on said` bar toeXert va atensioning pressurelon the `threadinan adjustedlpositionof the guide.`

In testimony' whereof we hereunto affix our signatures inthe presence ofi twogwitve cents each, by'adrssiiig' tIie'Comimssianei of iiatents, Washingtdmnc. f u 

